Could a nasal vaccine mean you never get Covid again? How it works, where to get one and everything you need to know

Could an inhaled powdered vaccine finally offer the chance to eradicate Covid for good?

The vaccine is designed to work in the respiratory tract, where the virus first enters the body. According to a study, the vaccine provides almost immediate protection against Covid – compared to conventional injected vaccines, which take up to 14 days to become fully effective.

The inhaled vaccine blocked both infection with the virus and the chance of spreading it to others.

Although injected Covid vaccines are highly effective at preventing someone from becoming seriously ill and have helped prevent some 14.4 million deaths worldwide since the start of the pandemic, they are not as effective in 2022, according to the Journal of Paediatrics and Child Health effective. effective in stopping mild infections – which can then be passed on to others.

Before Christmas, Covid cases started to skyrocket in Britain.

About 4.2 percent of people in England and Scotland tested positive on December 13 – around 2.5 million people – according to figures from the UK Health Security Agency UKHSA.

And as well as the short-term discomfort of being unwell, some will also develop a long bout of Covid.

Therefore, a vaccine that can eradicate the virus before it has a chance to make you sick could have major benefits. An inhaled version could also appeal to people with needle phobia, which the NHS estimates is around 10 per cent of the population.

This isn’t the only nasal vaccine in development – ​​so could this really mean the end of Covid as we know it?

How does the new vaccine work?

The vaccine is made from small beads that contain the protein unique to the virus that causes Covid. It is inhaled into the nose and absorbed through the blood vessels in the airways, where immune cells called T cells and B cells (which produce antibodies) attack it and then remember it.

Then, when the real virus arrives, these immune cells are ready to attack it quickly.

The results of the study, by researchers at the Chinese Academy of Sciences in Beijing and published in the journal Nature, were carried out on mice, hamsters and monkeys – but human trials are now expected.

Are inhaled vaccines better?

Giving a vaccine as a nasal spray means you generate a greater production of infection-fighting immune cells around the nose and mouth, which are the main entry points for Covid and other respiratory viruses, than you would normally get from an injected vaccine.

The area behind the nose (called the nasopharyngeal area) is lined with a mucous membrane that extends into the intestines and is rich in immune cells. Preparing these cells helps stop the virus before it can multiply and move through the body.

“If a vaccine is inhaled or given through the nose or mouth, it will prepare these cells, which are the first line of defense, to act quickly,” said Professor Muhammad Munir, a virologist at Lancaster University.

“An injected vaccine given into the muscle, usually in the arm, will also produce T cells and B cells, but these will mainly circulate in the blood and organs,” he adds.

‘Injected vaccines only produce a small amount in the nose and mouth, so they are not ideal guardians of the point of entry of the Covid virus.

“It’s like putting guards behind a wall: with a nasal vaccine you have those guards where you need them.”

Why do they work faster?

The big advantage is the speed at which antibodies generated in the nasal area will respond once the Covid virus is detected – meaning they will nip the infection before it manifests.

‘These nasal immune cells will block the infection within a few minutes – while the immune cells produced by the intramuscular vaccine will start working six to eight hours after the virus enters,’ says Professor Munir.

This should mean eradicating the virus before it has a chance to take hold and make someone unwell – and crucially – pass it on to others.

The latest study follows tests of a nasal vaccine carried out on animals by a team at the University of Maryland, reported in Nature Communications last November – which found it ‘significantly’ reduced Covid infection and transmission.

Any other benefits?

The fact that nasal vaccines are available in powder form is not only attractive to people with needle phobia, but also means that, unlike the injectables, they do not need to be refrigerated and can therefore be easily administered anywhere (not just here but also an advantage in developing countries). .

Furthermore, the vaccine reported in the latest Nature study is a single dose, unlike jabs, which may require two or three doses.

And the benefits of nasal vaccines could extend beyond Covid.

Peter Openshaw, professor of experimental medicine at Imperial College London, says inhaled vaccines “could have significant benefits in preventing (other) infections that enter through the lungs and nose.”

Does this mean I will never get Covid again?

Possibly, but it is unclear how long the protection of a nasal vaccine lasts.

Are standard vaccines not good enough?

The Covid shots administered into the arms are very good at preventing people from becoming seriously ill.

They have prevented 19.8 million Covid deaths worldwide since their introduction in 2020, according to a paper published in the Lancet in June 2022 – but they are not as effective at preventing transmission and stopping people from becoming infected as it new powder vaccine appears to be.

With the standard vaccine injection, protection varies depending on the vaccine and the variant it is targeting.

According to UKHSA, the Moderna booster provided as much as 90 to 95 percent protection against hospitalization with a Covid infection nine weeks after vaccination.

When it comes to catching Covid, after two weeks it offers 63 percent protection against the BA.1 Omicron variant and 70 percent against the BA.2 – but after 25 weeks that dropped to 9 percent protection against BA.1 and 13 percent against BA.2.

What are the disadvantages of nasal vaccines?

They need to be administered correctly – and there’s a chance someone might sneeze out the vaccine before it works.

“In theory that could happen,” says Andrew Easton, emeritus professor of virology at the University of Warwick.

Experts have raised concerns that the nose is lined with hair-like cells that could push any vaccine back into the stomach, potentially rendering it useless.

Some also fear that the rapid turnover of the cells of the mucous membrane means that any protection will be very short-lived.

However, there appear to be limited side effects. A study published in The Lancet in December involving 30,000 people given two doses of an intranasal Covid vaccine or a placebo two weeks apart found no serious side effects.

How soon might we have a nasal vaccine in Britain?

We already have them. Fluenz Tatra, a nasal vaccine containing a live but weakened form of the flu virus, is given to millions of children every year (but because it contains a live virus it is not suitable for the elderly because their immune systems are weaker).

On the Covid front, many nasal vaccines are in development around the world, and at least two in the US may be at a stage where they could be submitted to regulators later this year.

One of the contenders in Britain, called ViraVac, was developed by Professor Munir and his team from a vaccine that was originally sprayed into barns to stop a form of coronavirus in chickens.

This had shown promise in animal studies, but he says he has struggled to find the funding needed to move to the next phase of research since the World Health Organization downgraded Covid’s status, saying in May last year that it was ‘no longer a global problem’. emergency’.

In October 2022, news reports in China showed people receiving the world’s first Covid vaccine that is inhaled through the nose and mouth, a version of an injectable vaccine used as a booster in China. Its effectiveness is not yet clear.

Meanwhile, iNCOVAC, a Covid vaccine administered in the form of nasal drops (mainly available in private hospitals) as a primary vaccine or as a booster vaccine for those above 18 years of age, was approved for use in India in January last year.